Medicare, the federal health insurance program for people aged 65 and older or with certain disabilities, can seem overwhelming with its multiple parts. This guide breaks down Parts A, B, C, D, and Medigap, explaining what each covers, costs involved, and how they work together to help you make informed decisions.
What is Medicare?
Medicare provides health coverage primarily for Americans 65 and older, those with permanent disabilities, or end-stage renal disease (ESRD). It consists of four main parts: A (hospital insurance), B (medical insurance), C (Medicare Advantage), and D (prescription drugs). Original Medicare refers to Parts A and B, while private plans offer additional options.
Understanding these components is crucial as they determine out-of-pocket costs, covered services, and plan choices. Most beneficiaries qualify for premium-free Part A if they’ve paid Medicare taxes for at least 10 years, but all parts involve deductibles, copayments, or coinsurance.
Part A: Hospital Insurance
Part A covers inpatient hospital stays, skilled nursing facility care (after a qualifying hospital stay), hospice care, and some home health care. It does not cover long-term custodial care or most physician services during these stays.
For 2026, the inpatient hospital deductible is typically around $1,632 per benefit period (updated annually), with daily copayments for extended stays: $408 for days 61-90 and $816 for lifetime reserve days. Skilled nursing coinsurance is $204 per day for days 21-100.
- Inpatient hospital care at critical access hospitals
- Skilled nursing facilities (limited to rehabilitation, not long-term care)
- Hospice for terminally ill patients (comfort care, pain relief)
- Part-time home health aide services if skilled care is needed
Most people get Part A premium-free, but those with fewer than 30 quarters of Medicare-covered employment pay up to $557 monthly (2026 estimate based on prior years). Automatic enrollment occurs if receiving Social Security benefits.
Part B: Medical Insurance
Part B covers outpatient care, doctor visits, preventive services, durable medical equipment, and more. Beneficiaries pay a monthly premium (standard $185.00 in 2025, income-adjusted) and 20% coinsurance after the annual deductible ($240 in 2024, subject to change).
Key coverages include:
- Medically necessary doctor and outpatient services
- Preventive screenings (e.g., mammograms, diabetes tests, wellness visits at no cost)
- Ambulance, lab tests, X-rays, MRIs
- Durable equipment like wheelchairs, walkers
- Limited drugs (e.g., injections, chemotherapy in office settings)
Part B does not cover routine dental, vision, hearing aids, or most prescription drugs. Premiums fund only 25% of costs; the rest comes from general revenues. Late enrollment incurs a 10% penalty per year delayed.
Part C: Medicare Advantage
Part C (Medicare Advantage) are private plans that bundle Parts A, B, and often D. Approved by Medicare, they may offer extras like dental, vision, hearing, and gym memberships, but with network restrictions and potentially higher out-of-pocket costs.
In 2026, average premiums are low (around $18/month), but plans vary by location. They must cover everything Original Medicare does, often with copays instead of coinsurance. Enrollment is during Annual Enrollment (Oct 15-Dec 7) or Initial Enrollment Period.
| Feature | Original Medicare (A+B) | Medicare Advantage (C) |
|---|---|---|
| Coverage Scope | Hospital, medical | A+B + extras (dental, vision) |
| Provider Network | Any provider accepting Medicare | Plan network (HMOs, PPOs) |
| Out-of-Pocket Max | No cap | Yes, typically $8,850/year |
| Prescriptions | Separate Part D needed | Often included |
Choose Advantage if you prefer predictable costs and extras; stick with Original for broader provider choice.
Part D: Prescription Drug Coverage
Part D is standalone or bundled in Advantage plans, covering outpatient prescription drugs. Plans vary by formulary (drug list), with premiums averaging $55/month, deductibles up to $590 (2026), and coverage gaps.
Structure includes:
- Initial coverage (copays/coinsurance)
- Coverage gap (donut hole, now 25% cost-sharing)
- Catastrophic coverage (low copays after $8,000 out-of-pocket)
Not all drugs are covered; check plan formularies. Late enrollment penalty is 1% per month uncovered. Vaccines like flu shots are often covered under Part B or D.
Medigap (Medicare Supplement Insurance)
Medigap policies, sold by private insurers, help pay Original Medicare’s deductibles, coinsurance, and copays. Standardized plans (A-N) cannot be sold with Advantage.
Popular plans like G cover most gaps except Part B deductible. Premiums range $100-300/month based on age/location. Guaranteed issue rights apply during open periods; underwriting otherwise.
- Foreign travel emergency coverage (80% in some plans)
- No networks; works nationwide
- Not for prescriptions (that’s Part D)
How the Parts Fit Together
Original Medicare (A+B) offers flexibility but no out-of-pocket cap. Add Part D for drugs and Medigap for gaps. Medicare Advantage (C) bundles A+B+D (usually) with extras but limits providers.
Costs interact: High-income earners pay IRMAA surcharges on B and D premiums. Coordinate with Medicaid for low-income help.
Enrollment Periods
Key times:
- Initial (3 months before/after 65th birthday)
- General (Jan 1-Mar 31 for coverage starting April)
- Annual (Oct 15-Dec 7)
- Special (e.g., moving, losing employer coverage)
Missing windows triggers penalties.
What Medicare Doesn’t Cover
- Routine dental, vision, hearing aids/exams
- Long-term care, custodial home care
- Cosmetic surgery, acupuncture
- Most overseas care (some Medigap exceptions)
Advantage plans often add these.
Frequently Asked Questions (FAQs)
Q: Is Part A free?
A: Yes for most with 40 quarters of Medicare taxes paid; otherwise, premiums apply.
Q: Does Medicare cover prescriptions?
A: Not under A/B; requires Part D or Advantage plan with drug coverage.
Q: Can I have both Advantage and Medigap?
A: No; Medigap works only with Original Medicare.
Q: What if I work past 65?
A: Delay Part B to avoid premiums; employer coverage coordinates.
Q: How do I switch plans?
A: During Annual Enrollment; changes effective Jan 1.
Choosing the Right Medicare Plan
Assess health needs, budget, preferred doctors, and travel. Use Medicare.gov’s plan finder. Consult SHIP counselors for free advice. Review annually as plans change.
Medicare evolves; 2026 updates may adjust deductibles/premiums. Stay informed via official sites.
References
- Parts of Medicare — Centers for Medicare & Medicaid Services. 2025. https://www.medicare.gov/basics/get-started-with-medicare/medicare-basics/parts-of-medicare
- Overview of Medicare Parts A-D — National Library of Medicine, PMC. 2009-11-16. https://pmc.ncbi.nlm.nih.gov/articles/PMC2790649/
- What are the parts of Medicare? Part A, B, C, D explained — HealthPartners Blog. Recent (2024+). https://www.healthpartners.com/blog/parts-of-medicare-explained/
- Understanding Medicare’s Part A, B, C and D Options — AARP. 2024. https://www.aarp.org/medicare/understanding-medicare-the-plans/
- What’s the difference between Medicare parts A, B, C, and D? — YouTube (Medicare explainer). Recent. https://www.youtube.com/watch?v=JlWyxQhLrdo
This article is general information, not personal financial advice. Consider your own situation, or speak with a licensed adviser, before acting on it.
